scholarly journals Numerical and experimental investigation of flat-clinch joint strength

2022 ◽  
Author(s):  
Sandra Friedrich ◽  
Thoralf Gerstmann ◽  
Carolin Binotsch ◽  
Birgit Awiszus
Keyword(s):  
Sheet Metal ◽  
Joint Strength ◽  
Energy Savings ◽  
Process Development ◽  
Numerical Models ◽  
Good Alternative ◽  
Load Models ◽  
Neck Thickness ◽  
Load Tests ◽  
First Time

AbstractThe striving for energy savings by lightweight construction requires the combination of different materials with advantageous properties. For joining sheet metal components, clinching offers a good alternative to thermal joining processes. In contrast to thermal joining processes, the microstructure in the joining zone remains largely unaffected. Conventional clinch joints, however, have a protrusion on the underside of the joint, which restricts their use in functional and visible surfaces. Flat-clinching minimizes this disadvantage by using a flat anvil instead of a die. Due to the flatness on the underside, it can be used in visible and functional surfaces. This paper deals with the increase of joint strength by using an auxiliary joining element (AJE) in the second forming stage. To achieve optimum improvement in the joint strength of an aluminum Al99.5 H14 sheet metal joint and to save costs, the AJE was varied numerically in terms of volume, material and basic shape. The geometric parameters (e.g., interlocking f and neck thickness tn) do not allow direct derivation of the joint strength. For this reason, the 2D clinch model was extended for the first time to include 3D load models (cross tension, shear tension). To validate the numerical results, optimized flat-clinch joints with AJE and the associated load tests were implemented experimentally. The numerical models were used to improve the process development.

Design and evaluation of a wedge-type anchor for fibre reinforced polymer tendons

2000 ◽  
Vol 27 (5) ◽  
pp. 985-992 ◽  
Author(s):  
T I Campbell ◽  
N G Shrive ◽  
K A Soudki ◽  
A Al-Mayah ◽  
J P Keatley ◽  
...  
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Numerical Models ◽  
Ultra High Performance Concrete ◽  
Reinforced Polymer ◽  
Anchorage System ◽  
Fibre Reinforced Polymer ◽  
Load Tests ◽  
Tendon Tension ◽  
Post Tensioning

The development of a wedge-type anchorage system for fibre reinforced polymer (FRP) tendons, as part of an overall corrosion-free post-tensioning system, is outlined in this paper. A stainless steel anchor is described, and results from numerical models and load tests to evaluate its behaviour under loads from anchor set, as well as static and repeated tendon tension, are presented. An alternative wedge-type anchorage system made from ultra-high performance concrete is also described. It is shown that, although significant progress has been made in development of the anchorage, further work is required to make it more robust.Key words: FRP tendons, post-tensioning, anchorage, corrosion-free, mathematical models, load tests, concrete.

scholarly journals Innovation in Continuous Rectification for Tequila Production

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 283
Author(s):  
Estarrón-Espinosa Mirna ◽  
Ruperto-Pérez Mariela ◽  
Padilla-de la Rosa José Daniel ◽  
Prado-Ramírez Rogelio
Keyword(s):  
Energy Savings ◽  
Distillation Process ◽  
Distillation Columns ◽  
Continuous Rectification ◽  
New Process ◽  
Volatile Profiles ◽  
First Time ◽  
Continuous Distillation ◽  
Manual Mode ◽  
Rectification Process

In this study, a new process of continuous horizontal distillation at a pilot level is presented. It was applied for the first time to the rectification of an ordinario fraction obtained industrially. Continuous horizontal distillation is a new process whose design combines the benefits of both distillation columns, in terms of productivity and energy savings (50%), and distillation stills in batch, in terms of the aromatic complexity of the distillate obtained. The horizontal process of continuous distillation was carried out at the pilot level in a manual mode, obtaining five accumulated fractions of distillate that were characterized by gas chromatography (GC-FID). The tequila obtained from the rectification process in this new continuous horizontal distillation process complies with the content of methanol and higher alcohols regulated by the Official Mexican Standard (NOM-006-SCFI-2012). Continuous horizontal distillation of tequila has potential energy savings of 50% compared to the traditional process, besides allowing products with major volatile profiles within the maximum limits established by the regulation for this beverage to be obtained.

scholarly journals Functionalized Multiwalled CNTs in Classical and Nonclassical CaCO3 Crystallization

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1169 ◽  
Author(s):  
Andrónico Neira-Carrillo ◽  
Patricio Vásquez-Quitral ◽  
Marianela Sánchez ◽  
Masoud Farhadi-Khouzani ◽  
Héctor Aguilar-Bolados ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Good Alternative ◽  
Gas Diffusion ◽  
High Tech ◽  
Amorphous Calcium Carbonate ◽  
Multiwalled Carbon ◽  
Selective Crystallization ◽  
First Time ◽  
Functionalized Mwcnts ◽  
Multiwalled Cnts

Multiwalled carbon nanotubes (MWCNTs) are interesting high-tech nanomaterials. MWCNTs oxidized and functionalized with itaconic acid and monomethylitaconate were demonstrated to be efficient additives for controlling nucleation of calcium carbonate (CaCO3) via gas diffusion (GD) in classical as well as nonclassical crystallization, yielding aragonite and truncated calcite. For the first time, all amorphous calcium carbonate (ACC) proto-structures, such as proto calcite-ACC, proto vaterite-ACC and proto aragonite-ACC, were synthesized via prenucleation cluster (PNC) intermediates and stabilized at room temperature. The MWCNTs also showed concentration-dependent nucleation promotion and inhibition similar to biomolecules in nature. Incorporation of fluorescein-5-thiosemicarbazide (5-FTSC) dye-labeled MWCNTs into the CaCO3 lattice resulted in fluorescent hybrid nanosized CaCO3. We demonstrate that functionalized MWCNTs offer a good alternative for controlled selective crystallization and for understanding an inorganic mineralization process.

scholarly journals The homogenous alternative to biomineralization: Zn- and Mn-rich materials enable sharp organismal “tools” that reduce force requirements

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. M. S. Schofield ◽  
J. Bailey ◽  
J. J. Coon ◽  
A. Devaraj ◽  
R. W. Garrett ◽  
...  
Keyword(s):  
Abrasion Resistance ◽  
Energy Savings ◽  
Impact Resistance ◽  
Atom Probe ◽  
Nanometer Scale ◽  
Time Loss ◽  
Protein Residues ◽  
Mandibular Teeth ◽  
First Time ◽  
Measured Hardness

AbstractWe measured hardness, modulus of elasticity, and, for the first time, loss tangent, energy of fracture, abrasion resistance, and impact resistance of zinc- and manganese-enriched materials from fangs, stings and other “tools” of an ant, spider, scorpion and nereid worm. The mechanical properties of the Zn- and Mn-materials tended to cluster together between plain and biomineralized “tool” materials, with the hardness reaching, and most abrasion resistance values exceeding, those of calcified salmon teeth and crab claws. Atom probe tomography indicated that Zn was distributed homogeneously on a nanometer scale and likely bound as individual atoms to more than ¼ of the protein residues in ant mandibular teeth. This homogeneity appears to enable sharper, more precisely sculpted “tools” than materials with biomineral inclusions do, and also eliminates interfaces with the inclusions that could be susceptible to fracture. Based on contact mechanics and simplified models, we hypothesize that, relative to plain materials, the higher elastic modulus, hardness and abrasion resistance minimize temporary or permanent tool blunting, resulting in a roughly 2/3 reduction in the force, energy, and muscle mass required to initiate puncture of stiff materials, and even greater force reductions when the cumulative effects of abrasion are considered. We suggest that the sharpness-related force reductions lead to significant energy savings, and can also enable organisms, especially smaller ones, to puncture, cut, and grasp objects that would not be accessible with plain or biomineralized “tools”.

scholarly journals LLDPE Composites with Nanosized Copper and Copper Oxides for Water Disinfection

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1713
Author(s):  
Yanna Gurianov ◽  
Faina Nakonechny ◽  
Yael Albo ◽  
Marina Nisnevitch
Keyword(s):  
Cuprous Oxide ◽  
Copper Ions ◽  
Good Alternative ◽  
Copper Oxide Nanoparticles ◽  
Water Disinfection ◽  
Bacterial Suspension ◽  
Oxide Nanoparticles ◽  
Linear Low Density Polyethylene ◽  
Cuprous Oxide Nanoparticles ◽  
First Time

Consumption of contaminated water may lead to dangerous and even fatal water-borne diseases. Disinfection of drinking water is the most effective solution for this problem. The most common water treatment methods are based on the use of toxic disinfectants. Composites of polymers with nanosized metals and their oxides may become a good alternative to the existing methods. Expanding the scope of our previous publication, copper, cuprous, and copper oxide nanoparticles were immobilized onto linear low-density polyethylene by a simple thermal adhesion method. The antibacterial efficiency of the immobilized nanoparticles was tested against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus in batch experiments and for the first time the efficiency of these composites is reported for continuous flow regime. Immobilized copper and cuprous oxide nanoparticles demonstrated a high ability to eradicate bacteria after 30 min. These composites showed no or very limited leaching of copper ions into the aqueous phase both in the presence and in the absence of a bacterial suspension. Immobilized copper and cuprous oxide nanoparticles can be used for batch or continuous disinfection of water.

scholarly journals Development of a THMC code for bentonites in COMSOL Multiphysics

2020 ◽  
Vol 195 ◽  
pp. 04002
Author(s):  
Ángel Yustres ◽  
Rubén López-Vizcaíno ◽  
Virginia Cabrera ◽  
Vicente Navarro
Keyword(s):  
Reactive Transport ◽  
Transport Model ◽  
Numerical Models ◽  
Swelling Pressure ◽  
Double Porosity ◽  
Comsol Multiphysics ◽  
Chemical Potentials ◽  
Definition Of ◽  
High Degree ◽  
First Time

The proposed use of active clays for the isolation of radioactive wastes in deep geological repositories has been followed by a deeper understanding of this type of soils. This increased knowledge has led to the need for both conceptual and numerical models capable of capturing the main trends in behaviour and the different couplings between different physical-chemical phenomena. In addition, the model must have a high degree of flexibility that enables it to accommodate future developments or new relevant phenomena. This work presents a numerical THMC code developed entirely on the COMSOL Multiphysics numerical implementation platform, which provides the required adaptability. This model includes, for the first time in this environment, a reactive transport model in unsaturated porous media for a relevant geochemical system (consistent with the MX-80 bentonite) together with a THM model based on a double porosity approach. The chemical potentials of water and solutes are used for the definition of thermodynamic equilibria between both porosity levels. Trends in the behaviour of a bentonite sample under oedometric conditions are satisfactorily simulated in response to a process of saturation and change in salinity conditions. Variations in swelling pressure, porosity distribution or dissolution/precipitation of the main accessory minerals are analysed and explained by means of the proposed conceptual model.

scholarly journals Morphodynamics of a wave dominated embayed beach on an irregular rocky coastline

2018 ◽  
Vol 66 (2) ◽  
pp. 172-188 ◽  
Author(s):  
Mario Luiz Mascagni ◽  
Eduardo Siegle ◽  
Moysés Gonsalez Tessler ◽  
Samara Cazzoli y Goya
Keyword(s):  
Numerical Models ◽  
High Energy ◽  
Hydrodynamic Characteristics ◽  
Rip Currents ◽  
Field Surveys ◽  
Serra Do Mar ◽  
Hydrodynamic Processes ◽  
Tourism Potential ◽  
First Time

Abstract Wave-dominated embayed beaches on irregular rocky coastlines are highly appreciated for their landscapes and tourism potential. Yet our understanding about the interaction of the oceanographic processes with the geological inheritance in this type of beaches still needs further investigation to better understand their natural balance. In this study, we apply the classical approach of morphodynamics to describe for the first time the variations in the Boiçucanga beach morphology, an embayed beach located in São Sebastião City on an irregular rocky coastline that is well known for its beautiful beaches embedded in the valleys of Serra do Mar. Field surveys were performed over 15 months, between April 2008 and September 2009, seeking to evaluate the interactions among the morphology, sediments and hydrodynamic characteristics at Boiçucanga. All data generated during the field surveys have supported the application of the following morphodynamic models: Classification of morphological beach stages [O]; Number of nearshore sandbars [B*]; Relative tide range [RTR]; Beach exposure on embayed coasts [Ro/a and ß]; and Embayment beach scaling parameter [d] to determine the geomorphological behavior of the beach on monthly and annual time scales. From these models, Boiçucanga is classified as a deep embayed beach exposed to high-energy waves, with a predominant reflective profile, which favors the development of beach cusps and topographically controlled rip currents. The combined results of the field observations and applied models allowed us to better understand the role of geological heritage in the two morphodynamic signatures found at the same beach arch. For future studies, we will focus on numerical models to increase the understanding of the hydrodynamic processes that govern the sediment transport in Boiçucanga.

Fatigue Failure Behaviour Study of Automotive Lower Suspension Arm

2011 ◽  
Vol 462-463 ◽  
pp. 796-800 ◽  
Author(s):  
Nawar A. Kadhim ◽  
Shahrum Abdullah ◽  
Ahmad Kamal Ariffin ◽  
S.M. Beden
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Numerical Models ◽  
Good Alternative ◽  
Analysis Tool ◽  
Element Analysis ◽  
Finite Element Software ◽  
Life Model ◽  
Experimental Process ◽  
Behaviour Study

Fatigue life of automotive lower suspension arm has been studied under variable amplitude loadings. In simulation, the geometry of a sedan car lower suspension arm has been used. To obtain the material monotonic properties, tensile test has been carried out and to specify the material mechanical properties of the used material, a fatigue test under constant amplitude loading has been carried out using the ASTM standard specimens. Then, the results used in the finite element software to predict fatigue life has been evaluated later to show the accuracy and efficiency of the numerical models which they are appreciated. The finite element analysis tool is therefore proved to be a good alternative prior to the further experimental process. The predicted fatigue life from the simulation showed that Smith-Watson-Topper model provides longer life than Morrow and Coffin-Manson models. This is due to the different consideration for each strain-life model during life calculations.

A Two-Pronged Approach for the Assessment of Springback Variability for Sheet Metal Forming Applications

2013 ◽  
Vol 554-557 ◽  
pp. 957-965 ◽  
Author(s):  
Jérémy Lebon ◽  
Guénhaël Le Quilliec ◽  
Rajan Filomeno Coelho ◽  
Piotr Breitkopf ◽  
Pierre Villon
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Numerical Models ◽  
Low Cost ◽  
Forming Process ◽  
Metal Forming Process ◽  
Small Random Perturbations ◽  
Complex Phenomena ◽  
Bending Under Tension

Springback assessment for sheet metal forming processes is a challenging issue which requires to take into account complex phenomena (physical non linearities and uncertainties). We highlight that the stochastic analysis of metal forming process requires both a high precision and low cost numerical models and propose a two-pronged methodology to address these challenges. The deep drawing simulation process is performed using an original low cost semi-analytical approach based on a bending under tension model with a good accuracy for small random perturbations of the physical and process parameters. The springback variability analysis is performed using an efficient stochastic metamodel, namely a sparse version of the polynomial chaos expansion.

scholarly journals Evidence for energy savings from aerial running in the Svalbard rock ptarmigan ( Lagopus muta hyperborea )

2011 ◽  
Vol 278 (1718) ◽  
pp. 2654-2661 ◽  
Author(s):  
R. L. Nudds ◽  
L. P. Folkow ◽  
J. J. Lees ◽  
P. G. Tickle ◽  
K.-A. Stokkan ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Energy Savings ◽  
Metabolic Energy ◽  
Current Evidence ◽  
Cost Of Transport ◽  
Walking Gait ◽  
High Speeds ◽  
Lagopus Muta ◽  
Metabolic Energy Expenditure ◽  
First Time

Svalbard rock ptarmigans were walked and run upon a treadmill and their energy expenditure measured using respirometry. The ptarmigan used three different gaits: a walking gait at slow speeds (less than or equal to 0.75 m s −1 ), grounded running at intermediate speeds (0.75 m s −1 < U < 1.67 m s −1 ) and aerial running at high speeds (greater than or equal to 1.67 m s −1 ). Changes of gait were associated with reductions in the gross cost of transport (COT; J kg −1 m −1 ), providing the first evidence for energy savings with gait change in a small crouched-postured vertebrate. In addition, for the first time (excluding humans) a decrease in absolute metabolic energy expenditure (rate of O 2 consumption) in aerial running when compared with grounded running was identified. The COT versus U curve varies between species and the COT was cheaper during aerial running than grounded running, posing the question of why grounded running should be used at all. Existing explanations (e.g. stability during running over rocky terrain) amount to just so stories with no current evidence to support them. It may be that grounded running is just an artefact of treadmill studies. Research investigating the speeds used by animals in the field is sorely needed.

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